1. Field of the Invention
The invention relates to a cooled gas-turbine blade of solid construction.
2. Discussion of Background
Cooled gas-turbine blades are designed as hollow blades (DE-A 32 43 161--United Technologies), the outer walls of which are reinforced by internal ribs, which at the same time form at least one large cooling passage, which runs meander-like. A plurality of flow-diverting ribs and flow-separation beads are fitted at the walls into this large cooling passage in order to create a turbulent flow and thus encourage cooling. The cooling medium flows out through the blade walls and mixes with the fuel gas of the turbomachine.
A cooled turbine blade constructed in such a way is extremely complicated to manufacture and requires a very high degree of precision during manufacture. The manufacturing costs are in particular also very high because the blades resemble spatially twisted airfoils. In addition, a closed cooling circuit cannot be constructed, since the cooling medium is drawn off via fuel gas of the turbo-plant. In addition, the cooling in the various corners and angles in the interior of the cooled turbine blade is very difficult, since flow-diverting elements, which also permit a gas flow in these corners, have to be fitted. Such fitted parts make the manufacture of such turbine blades expensive and complicated. Yet overheating of the material may still occur in such corners.